Disposable absorbent articles find widespread use as personal care products such as diapers, children's toilet training pants and other infant and child care products, adult incontinence garments and other adult care products, sanitary napkins and other feminine care products and the like, as well as surgical bandages and sponges. These articles absorb and contain body waste and are intended to be discarded after a limited period of use, i.e., the articles are not intended to be laundered or otherwise restored for reuse. Conventional disposable absorbent articles comprise an absorbent body disposed between an inner layer adapted for facing and typically contacting the wearer's skin and an outer layer for inhibiting liquid waste absorbed by the absorbent body from leaking out of the article. The inner layer of the absorbent article is typically liquid permeable to permit body waste to pass therethrough for absorption by the absorbent body.
Disposable absorbent training pants, in particular, are useful in toilet training children. Typically, these training pants are similar to washable, cloth underwear in the manner in which they are put on and worn, yet provide an absorbent function similar to conventional diapers. Training pants are designed to provide a child undergoing toilet training with a garment that eases the transition from diapers to washable, cloth underwear as they become more confident in their ability to use the toilet independently. Indeed, one important aspect of the total toilet training process is the change from diapers to training pants to help the child understand that he or she should now use the toilet. Although the use of training pants and positive encouragement from the caregiver has been helpful in the toilet training process, there is still much room for improvement.
One motivational mechanism used to encourage such a transition is the use of disposable training pants that more closely resemble an actual pair of underwear. Specifically, a child is encouraged to wear a garment that resembles underwear worn by older children. To mimic the appearance of underwear and raise the interest of a child during toilet training, training pants are known to have graphics that are visible from outside the pants, such as by being applied to their exterior or outer surface. The graphics may be in the form of a character, object and/or alphanumeric (e.g., numbers, words, phrases, instructions, etc.). Graphics applied to such disposable articles may also provide visual assistance to the wearer or to the caregiver securing the article on the wearer.
Another motivational mechanism used to encourage or facilitate a child's transition to regular underwear is the use of wetness indicators, which are devices design to indicate to the wearer and/or caregiver when a bodily fluid has been released into the article (e.g., when a wearer urinates into the absorbent article). Various types of moisture or wetness indicators have been used in absorbent articles. Known wetness indicators include various passive indicators such as indicator strips, printing, or other devices secured or otherwise formed within each absorbent article. Some wetness indicators include suitable alarm devices that are designed to send a signal when the wetness indicator senses moisture or wetness. The alarm devices can produce an audible, tactile, electromagnetic, or visual signal.
In some embodiments, inexpensive conductive threads, foils, or paper have been placed in absorbent articles with wetness indicators. The conductive materials serve as conductive leads for a signaling device and form an open circuit in the article that can be closed when a fluid, such as urine, closes the circuit. In these embodiments, although the absorbent articles having the conductive threads, foils, or paper therein are disposable, the signaling devices are typically not. Thus, the signaling devices are intended to be removed from a used article and reattached to a subsequent, new article.
Several technologies have enabled wetness detection with little to no product alteration using non-invasive sensors that can be removably placed on the absorbent article. By way of example, U.S. Patent Application Publication No. 2010/0168694, which is incorporated herein by reference, discloses an infrared wetness detection system for an absorbent article that includes a non-invasive sensor that measures infrared reflectance at some depth within the absorbent article. U.S. Pat. No. 8,274,393, which is incorporated herein by references, discloses the use of various sensors, such as a temperature sensor, a conductivity sensor, a humidity sensor, a chemical sensor, a vibration sensor, or a material expansion sensor placed on an outside cover of an absorbent article. U.S. Pat. No. 8,207,394, which is incorporated by reference herein, discloses the use of an induction coil sensor for wetness detection in an absorbent article. U.S. Patent Application Publication No. 2010/0168702, which is incorporated herein by reference, discloses a non-invasive capacitive sensor system and associated circuitry for wetness detection.
While a non-invasive signaling device provides many advantages, problems can be encountered in properly associating a particular signaling device with a proprietary product. In particular, due to the non-invasive nature of such signaling devices, a proprietary signaling device can be used with any absorbent article, regardless of the manufacturer or source of the absorbent article. Moreover, non-invasive signaling devices can be used on products that have not been safety cleared for use with a signaling device.
U.S. Patent Application Publication No. 2012/0116337, which is incorporated herein by reference, discloses a non-invasive signaling device capable of detecting the presence of one or more identifiable characteristics on the absorbent article. In particular, the absorbent article can be manufactured with a particular identifiable characteristic that can be sensed or detected by the non-invasive signaling device. When the non-invasive signaling device detects the presence of the identifiable characteristic on the absorbent article, the non-invasive signaling device is permitted to operate to detect the presence of fluid in the absorbent article. If the signaling device is used on an absorbent article that does not include the identifiable characteristic, the non-invasive signal will not operate, thereby preventing the use of a proprietary signaling device on an unauthorized product.
In one embodiment disclosed in U.S. Patent Application Publication No. 2012/0116337, the identifiable characteristic is a predefined color. In another disclosed embodiment, the identifiable characteristic is a conductive pattern printed on the absorbent article. If the predefined color or the electrical characteristics of the printed conductive pattern falls within a predefined range, the signaling device will be permitted to operate. However, one potential issue with both of these embodiments is that the predefined color and the printed conductive pattern are readily visible exterior the absorbent article. As a result, the predefined color or printed conductive pattern potentially diminishes the visual quality of any graphics printed on the exterior of or otherwise visible exterior the absorbent article.
In view of the above, a need currently exists for an absorbent article having one or more identifiable characteristics that are detectable by a non-invasive signaling device and that do not diminishes the visual quality of any graphics printed on the exterior of or otherwise visible exterior the absorbent article.